Changes In Fatty Acid Content Research Articles

Effect of growth phase on the fatty acid composition of Thermus spp.

Two yellow and two red pigmented strains of Thermus were monitored for changes in fatty acid content and composition with reference to growth phase at the optimum temperature. Fatty acid content per mg of dry weight increased as the cultures aged. In addition the quantities of iso C 15:0, iso C 17:0 and iso C 16:0 increased in yellow pigmented strains, but in red pigmented strains, an increase was seen in iso C 15:0, but C 16:0 and iso C 16:0 levels decreased. Thus the fatty acid composition of these organisms varies with growth phase, and shows also strain specific variability.

Glycerolipid synthesis in isolated adipocytes: substrate dependence and influence of norepinephrine.

Studies of fatty acid (FA) esterification by adipocytes have led to conflicting views with respect to how the process is regulated by norepinephrine (NE). It remains unclear whether NE directly modulates the pathway or whether its effects are indirect and reflect its well-known action to activate lipolysis. Changes in lipolysis can complicate estimation of esterification rates by altering both medium FA and the hydrolysis of newly formed FA esters. In this report, we describe an experimental approach that determined the effect of NE on FA esterification, amidst the complications introduced by activation of lipolysis. Esterification rates were estimated from the simultaneous incorporations (0.1-60 min) of [14C]glucose and [3H]oleate into diglyceride (DG), phospholipid (PL), and triglyceride (TG). Saturation kinetics of incorporation rates, with respect to FA, and more specifically to unbound or albumin-free FA (ubFA), were determined in both basal and NE-treated cells. To obtain true estimates of ester synthesis, incorporation rates were adjusted for label loss from breakdown of labeled esters. Our findings were: 1) In basal versus NE-treated cells, [3H]oleate, on its pathway to esterification, was diluted, respectively, by 2 and 50% of measured cell FA, and the diluting FA appeared derived from lipolysis. 2) Syntheses of PL, DG, and TG, estimated from incorporation of [14C]glucose, saturated at low ubFA. The Km for TG synthesis (0.06 microM) was within the physiological range of ubFA which meant that changes in plasma FA will modulate TG synthesis. PL synthesis, on the other hand (Km less than 0.01 microM), would be largely saturated under physiological conditions. 3) NE treatment increased the molar ratio of FA to albumin in the medium an average 8-fold and ubFA about 87-fold. In addition, NE accelerated hydrolysis of labeled PL and DG. Adjusting incorporation rates for these changes indicated that NE does not directly regulate glyceride synthesis. The assays described should allow estimation of glycerolipid synthesis under various metabolic or disease states and will distinguish direct effects from those reflecting changes in FA concentration or in hydrolysis of labeled FA esters.

Characterization of Gamma Irradiated Peanut Kernels Stored One Year Under Ambient and Frozen Conditions

ABSTRACTPeanut kernels were gamma irradiated at 0, 2.5,5.0,10, and 20 KGy, and stored 1 yr at ambient and frozen (− 14°C) conditions. Irradiated peanuts lost germination capabilities during storage. Molds were detected only on peanuts irradiated with 2.5 KGy and stored at ambient temperature. Peanut oil in kernels stored at − 14°C was comparatively more stable than that in peanuts stored at ambient temperature. Oxidation of oil was not significantly changed by irradiation. Changes in fatty acid content varied slightly with exception of linoleic and linolenic acids which decreased with increased radiation depending on storage temperature. The SDS‐PAGE protein patterns of peanuts revealed no noticeable variation of protein subunits resulting from irradiation and storage.

THE INFLUENCE OF ALTERNATING TEMPERATURES ON GERMINATION AND FATTY ACID CONTENT OF APPLE SEEDS

Seeds of `Golden Delicious' apple (Malus domestic a Borkh.) were exposed to constant and alternating chilling temperatures. Germination was reduced in seeds treated with 4/11, 4/13, and 4/15 C for 16/8 h, respectively, compared to those treated at a constant temperature (4 C). The 4 C reached 100 % germination after 1600 h, the 4/11 C after 1864 h, and the 4/13 C after 1973 h at 4 c. The 4/15 C never reached complete germination even after 2200 at 4 C. The predominant fatty acids during stratification at constant and alternating temperatures were palmitic, oleic, and linoleic acids. Stearic acid was found at a lower level. Arachidic and behenic acids were only found in constant temperature treatment. There were no significant changes in fatty acid content during stratification at constant and alternating temperatures except that the 4/11 C treatment increased levels of palmitic, oleic, and linoleic acids.

Alteration of α‐Tocopherol Content in the Developing and Aging Peripheral Nervous System: Persistence of High Correlations with Total and Specific (n‐6) Polyunsaturated Fatty Acids

In contrast to brain, the sciatic nerve concentration of vitamin E in rats increased rapidly during the postnatal period (approximately fivefold between days 1 and 8), then decreased dramatically (about twofold between days 8 and 30), and further decreased slowly between days 30 and 60 and remained constant up to 2 years. Although the sciatic nerve concentration of vitamin E decreased by 58% between days 8 and 30, the concentration of vitamin E in serum presented a marked decrease (approximately 75%). The vitamin E concentrations varied in a similar pattern in whole sciatic nerve and in endoneurium and showed a very close correlation (r = 0.94). The age-related changes in fatty acid concentration of the endoneurial fraction of the sciatic nerve were characterized by a large increase in content of saturated and monounsaturated fatty acids up to 6 months (twofold for saturated and fourfold for monounsaturated fatty acids). Then, up to 24 months, the amount of these fatty acids decreased very slowly. The content of (n-6) polyunsaturated fatty acids (PUFAs) decreased rapidly up to 1 year and slowly afterward. In contrast, during development the amount of (n-3) PUFA was relatively stable and decreased during aging. A highly significant correlation between vitamin E and (n-6) PUFA [18:2(n-6), 20:4(n-6), and total (n-6)] was observed but not between (n-3) PUFA and vitamin E. It is suggested that there may be a relationship between vitamin E and (n-6) PUFA in the PNS membranes during development and aging.

Replacement of molecular species of phosphatidylcholine: influence on erythrocyte Na transport

The phosphatidylcholine-specific transfer protein (PC-Tp) from bovine liver was used to replace endogeneous erythrocyte phosphatidylcholine (PC) with various amounts of five different molecular species of PC. Furosemide-sensitive (FS) Rb uptake, Na-Li exchange, and Na-K pump rates were considered in relation to the nature and extent of those replacements. Changes in fatty acid contents of PC after incorporation of different molecular species fell within a variation range (10-30%) similar to that found in large populations of healthy individuals. Di16:0-PC accelerated Na-Li exchange and FS Rb uptake by approximately 40 and 25%, respectively. Some reduction (20%) in FS Rb uptake was seen in 16:0/18:2-PC-enriched erythrocytes. Incorporation of 16:0/22:6-PC accelerated Na-Li exchange and FS Rb uptake by greater than 40 and 20%, respectively. Apart from inhibitory effects of 16:0/18:1-PC and di16:0-PC (24 and 19%, respectively) the Na-K pump rate was virtually unchanged by incorporation of different PC molecular species. Exogeneous PC molecules are exclusively inserted in the outer membrane leaflet and, particularly in the case of di16:0-PC, migrate slowly to the cytoplasmic leaflet. Prolonged incubation of cells (up to 21 h) after replacement with di16:0-PC showed that both Na-Li exchange and FS Rb uptake rates responded differently to redistribution of newly inserted molecules over both bilayer halves. Compared with cells exhibiting a selective incorporation of di16:0-PC in the outer monolayer, additional enrichment with disaturated species in the inner monolayer accelerated FS Rb uptake, whereas Na-Li exchange rate reverted to control values. It is concluded that small changes in fatty acid composition of PC induced by limited replacement of phospholipid molecular species can cause considerable changes in Na-Li exchange rate and FS Rb uptake. Differences in phospholipid molecular species composition could contribute to known interindividual variability of both Na-Li exchange and Na-K cotransport.

Physicochemical characteristics and flora of diarrhoeal and recovery faeces in children with acute gastroenteritis in Kenya

Physiochemical characteristics and flora of diarrhoeal and recovery faeces were investigated in 14 Kenyan children with acute gastro-enteritis. Causative micro-organisms were Shigella, Campylobacter, enterotoxigenic Escherichia coli, rotavirus and unknown in 6, 2, 1, 2 and 3 patients, respectively. The mean values of the pH of the diarrhoeal specimens were significantly higher than those of the recovery specimens. Large amounts of acetic acid and many other kinds of fatty acids were detected in the recovery specimens, but small amounts and few kinds of fatty acids were detected in the diarrhoeal specimens. Bacterial counts of anaerobic organisms, such as Bacteroides, Bifidobacterium, Lactobacillus and Eubacterium, were lower in the diarrhoeal specimens than in the recovery ones. The normal anaerobic intestinal flora is remarkably disturbed in patients with acute gastro-enteritis. This may result in changes in fatty acid contents and in the pH of diarrhoeal faeces.

Increased levels of vaccenic acid in bronchogenic carcinoma tissue.

Employing capillary gas liquid chromatography the levels of palmitic, palmitoleic, stearic, oleic, cis-vaccenic, linoleic, arachidonic and docosahexaenoic acids were measured in lung tissue and lung tumours from 28 patients undergoing surgery for bronchogenic carcinoma. There were significant increases in the majority of fatty acids in tumour tissue compared to normal tissue when the results were expressed in absolute units. However, when the relative changes in fatty acid concentration were studied, the most consistent findings were a significant rise in vaccenic acid and a fall in palmitic acid in tumour tissue compared to normal tissue. This change in the vaccenic:palmitic acid ratio may reflect specific changes in fatty acid metabolism in bronchogenic carcinoma tissue involving a delta-9 desaturase.

Patterns of fatty acid deposition during development of soybean seed

Fatty acid deposition in developing soybean seeds of high- and low-linolenic acid cultivars show a great deal of similarity. In all cultivars, the greatest change in fatty acid content occurs during the first half of seed formation. The amount of linolenic acid is highest during the very early stage of seed formation and the relative amount decreases thereafter. Linolenic acid content in mature soybean seed is inversely proportional to that of oleic acid.

Changes in renal phospholipid fatty acids in diabetes mellitus: correlation with changes in adenylate cyclase activity.

Male Sprague-Dawley rats made diabetic with alloxan (37.5 mg/kg) or streptozotocin (65 mg/kg) were killed after 3-6 weeks of disease; renal tissues were studied for phospholipid content and for fatty acid composition of the phospholipids. No consistent change was noted in total phospholipid content nor in the proportion of various phospholipids in diabetics. However, diabetic animals showed a consistent reduction of arachidonic acid content in phosphatidylcholine (PC) and phosphatidylethanolamine in whole renal cortex, plasma membranes purified from renal cortex, and in isolated glomeruli. Associated with the fall in arachidonic acid was a rise in linoleic acid in the samples studied. Insulin therapy returned the fatty acid profiles to normal. These results are similar to patterns observed in other diabetic tissues and suggest that diabetes is associated with generalized changes in cell membranes. That these structural changes may have functional significance is suggested by demonstrated alterations in the temperature-dependence of adenylate cyclase in renal plasma membranes of diabetic animals. Adenylate cyclase is thought to be intimately associated with PC in plasma membranes, a phospholipid showing significant changes in fatty acid content in diabetes (unsaturation index 165 +/- 2 for normals, 147 +/- 5 for diabetics). Na+,K+-ATPase which is thought to be primarily associated in vivo with phosphatidylinositol (PI), shows no change in apparent energy of activation in diabetes. The fatty acid content of PI is minimally altered in diabetes, and the unsaturation index is unchanged.

Fatty acid accretion during perinatal brain growth in the pig. A model for fatty acid accretion in human brain

1. 1. Brain fatty acid composition in the fetal, full term and postnatal piglet was analyzed. 2. 2. Changes in fatty acid content of developing pig brain parallel those found in the human. 3. 3. Total fatty acids per gram of brain increase with post conceptional age. 4. 4. Brain concentration of long chain derivatives of essential fatty acids, C18:2ω6 and C18:3ω3 increase during gestation while levels of shorter chain precursors ( C18:2ω6 and C18:3ω3) remain low. 5. 5. The results indicate that the developing piglet is an appropriate model, analogous to the human, for studies of changes in brain fatty acid content during neural development throughout the perinatal period.

Change in Fatty Acid Content of Polar Lipids during Ageing of Seeds of Peanut (Arachis hypogea L.)

Seeds of two cultivars of peanuts (Arachis hypogea L.) were harvested in different seasons and stored in 5 °C for different periods (2 and 38 months). The seeds stored for the longer period had a lower germination, leached more electrically conducting material when soaked in distilled water for 24 h, and had lower contents of fatty acids in polar lipid fractions. The fatty acid compositions of neutral lipid, glycolipid, and phospholipid fractions were similar in the differently aged seeds. Hydroperoxides could not be detected. Seeds of one cultivar were rapidly aged in an environment of 38 °C and 90% relative humidity. During 28 d, germination fell from 95% to 15%, leaching of electrically conducting material increased about 5-fold, and the content of fatty acids in polar lipid fractions fell to almost 10% of the original. The negative relationship between leaching and germination approximated closely to a straight line. Most of the decline in content of fatty acids from polar lipids preceded most of the change in germination and leaching. The fatty acid compositions of the different lipid fractions were almost unchanged. This, together with the actual fatty acid compositions, proved that some factor other than peroxidation was involved in the lipid deterioration, and peroxidation was probably unimportant. Loss of control over subcellular compartmentation or intracellular concentrations of metabolites, resulting from loss of membrane lipids, may have been the cause of the loss of viability.

Phospholipids in the liver of the pregnant rat: Changes in fatty acid content and composition

Pregnancy in the rat was associated with changes in hepatic phospholipids. All changes returned to the prepregnancy levels 2 to 3 weeks postpartum. The total phospholipid content was reduced significantly, mainly representing a reduction of phosphatidylcholine, -ethanolamine, and lysophosphatidylcholine fractions. Hepatic fatty acid content was also reduced and the composition was modified since both saturated and unsaturated acyl components were decreased with more pronounced changes in unsaturated acids. Total liver saturated fatty acids with 14 to 16 carbon atoms remained unaltered; stearic acid was reduced and arachidic and lignoceric acids were elevated. Among unsaturated fatty acids, palmitoleic, oleic, eicosatrienoic, arachidonic, eicosapentaenoic, and docosapentaenoic were decreased, docosatrienoic and docosahexaenoic were raised, whereas eicosaenoic and eicosadienoic did not change. In the phosphatidylcholine and -ethanolamine fractions, unsaturated acyl components also showed significant reduction. By and large they reflected the fatty acid changes occurring in total liver with the exception of the docosahexaenoic acid which was diminished in both fractions. The overall effect of pregnancy thus indicated a modification in unsaturated fatty acid content leading to the construction of less fluid membranes which may be responsible for the reduced enzyme activity of the endoplasmic reticulum.

Changing fatty acid composition during somatic embryogenesis in cultures of Daucus carota

The fatty acid composition of five embryo stages following the induction of embryogenesis in cultures of Daucus carota have been studied. Quantitative rather than qualitative changes in fatty acid content were observed, although globular embryos do possess some fatty acids of long (C 20 and above) chain length not observed in earlier or later stages in development. The major fatty acids present were C 16:0, 18:0, 18:1, 18:2 and 18:3.

Induction of reciprocal translocation in mice by triethylenemelamine

The incorporation of omega-3 polyunsaturated fatty acids (PUFA) in the egg is dependent on both the transfer efficiency of preformed dietary omega-3 fatty acids to the eggs as well as endogenous PUFA metabolism and deposition. Employing an experimental design consisting of 70 Lohmann LSL-Classic hens (n=10/treatment) in a 6-week feeding trial, we examined the impact of graded levels of either flaxseed oil (alpha-linolenic acid, ALA) or algal DHA (preformed docosahexaenoic acid, DHA), each supplying 0.20%, 0.40% and 0.60% total omega-3s. The control diet was practically low in omega-3s. Study parameters included monitoring the changes of fatty acid contents in yolk, measures of hen performance, eggshell quality, total lipids and fatty acid contents of plasma. Data were analysed as a complete randomized design using Proc Mixed procedure of SAS. No significant differences were observed between treatments with respect to hen performance, eggshell quality and cholesterol content in plasma and egg yolk. Individual and total omega-3 PUFA in the yolk and plasma increased (P<0.0001) linearly as a function of total omega-3 PUFA intake. At the highest inclusion levels, DHA-fed hens incorporated 3-fold more DHA in eggs compared with ALA-fed hens (179±5.55 vs. 66.7±2.25 mg/yolk, respectively). In both treatment groups, maximal enrichment of total n−3 PUFA was observed by week-2, declined by week-4 and leveled thereafter. In addition, accumulation of DHA in egg yolk showed linear (P<0.0001) and quadratic (P<0.05) effects for flaxseed oil (R2=0.89) and algal DHA (R2=0.95). The current data, based on defined level of total omega-3s in the background diet, provides evidence to suggest that exogenous as well as endogenous synthesis of DHA may be subject to a similar basis of regulation, and serve to highlight potential regulatory aspects explaining the limitations in the deposition of endogenously produced omega-3 LCPUFA.

Change in Fatty Acid Content of Fungus-Host Tissue During Pathogenesis of Uromyces phaseoli typica on Phaseolus vulgaris

Change in Fatty Acid Content of Fungus-Host Tissue During Pathogenesis of Uromyces phaseoli typica on Phaseolus vulgaris

Fatty acid concentrations in synchronous cultures ofChlorella pyrenoidosa, grown in the presence and absence of glucose

Total cellular fatty acids, of a high-temperature strain ofChlorella pyrenoidosa, were measured during a synchronous growth cycle in continuous light in the presence and absence of glucose.The fatty acid composition, consisting of saturated monoenoic, dienoic, and trienoic C(16) and C(18) fatty acids, remained essentially the same whether or not the cells were grown on glucose.Nearly all of the fatty acids increased irregularly in concentration during the growth cycle, showing a periodism during the prenuclear and cell-division stages of growth. Cultures exposed to glucose showed a more pronounced drop in the concentration of most of the fatty acids during both stages.None of the fatty acid concentrations, some of which have been implicated in the Hill reaction of a number of photosynthetic organisms, reflected the periodism in photosynthetic activity which was previously observed during the synchronous growth cycle of this organism.The changes in fatty acid concentration are discussed with relation to concurrent metabolic and cytological changes during cell maturation in this organism.

Fatty acid synthesis in vivo in maternal and fetal tissues in the rat

Fatty acid synthesis in vivo in maternal and fetal tissues in the rat

Fatty Acid Composition of Embryonic Fat Organ Lipids

THE PERIODICITY in the deposition of lipid material in the fat organs of the embryonic chick has been previously reported in an earlier paper from the author’s laboratory (Feldman et al., 1962a). The accumulation of lipid material in the fat organ was very rapid during the period of the thirteenth to the seventeenth day and was probably due to the transport of yolk lipids to the fat organs by means of serum lipoproteins. The metabolic change that occurs after this period includes the synthesis of triglyceride by the fat organ; and, in addition, the carbohydrate and amino acid metabolism is profoundly altered (Feldman et al., 1962b).It is not unreasonable to assume that if triglyceride synthesis did occur at approximately seventeen days of incubation, the event would be marked by a change in the fatty acid content of the tissue. Furthermore, these changes in fatty acid content would be apparent …